Mac OS X includes a copy of Mac OS 9.1 so you can use your Classic Mac OS 9 applications natively in Mac OS 9.1 or in the Classic compatibility environment in Mac OS X. To use a Classic application, just double-click it. The Classic environment starts automatically. Be sure to update your installation to Mac OS 9.2.1 for improved Classic application compatibility. Mac OS 9.2 supports Mac OS X compatible computersYou can install this version of Mac OS 9.2 on any of the following computers: Power Mac G4, Power Macintosh G3, PowerBook G4, PowerBook G3 (except the original PowerBook G3), iMac, and iBook.